This competing renewal application seeks support for the continuation of a highly successful Physician-Scientist Program in Aging at Harvard Medical School's Division on Aging and its affiliated institutions. This joint effort involving investigators in basic and clinical departments has excelled in identifying and training outstanding clinicians for research careers in areas central to the mission of the National Institute on Aging. In the previous two finding periods, we have successfully selected 18 superb physician-scientists who are now well- directed toward gerontologic research careers. We have also successfully influenced their mentors/sponsors in pursuing aging-related issues in their respective scientific disciplines, thereby recruiting these renowned basic scientists to contemplate and address fundamental questions in the field of aging. The major goal in the next funding period will be to provide exciting opportunities for additional outstanding physicians to engage in intensive training experiences involving didactic and laboratory experiences in the basic and clinical sciences. Four research areas will be emphasized: (1) cardiovascular disease, (2) cell proliferation disorders, (3) neurodegenerative disease, (4) and endocrine/renal dysfunction. Enlarged scope and improved quality of the training program will ensure that the Physician-Scientist trainees will be introduced to the current biological concepts and technical aspects of basic science investigation (Phase I) and will apply such expertise toward the elucidation of mechanisms of aging and clinically relevant problems in the elderly (Phase II). A special feature of the present application is the continuation of a greatly expanded program of enrichment activities for the trainees that are identified not only with this program but with other NIA-related research training programs. The ultimate goal of the program is the development of Physician-Scientists who can advance knowledge and enhance the development of academic, research-intensive programs in the long-neglected areas of biomedical Gerontology and Geriatrics.